This invention pertains to fabrication of electronic devices such as integrated circuits; more specifically, this invention relates to methods and compositions to improve the adhesion between gapfill metals and dielectrics for electronic devices.
Electroless deposition is a process that is frequently used in the fabrication of electronic devices. The process is particularly important for applications requiring deposition of metal layers such as gapfill metal on substrates comprising metal surface areas and dielectric surface areas such as structures for damascene and/or dual damascene devices. These processes are also in use for applications such as forming electrical connections to metal contacts for integrated circuits. Electroless deposition processes can readily proceed on certain catalytic or activated surfaces. The adhesion to the catalytic or activated surfaces may be satisfactory. Similarly, chemical vapor deposition processes used for depositing metals on the metal surfaces may also have satisfactory adhesion. However, metals deposited by electroless deposition and metals deposited by chemical vapor deposition may have poor adhesion to dielectric surfaces. Consequently, the deposited metals may be attached or held only by the metal surface areas of the substrate. Such surfaces may provide only a small portion of the contact surface area in comparison to contact with the dielectric surfaces and the overall adhesion of the metal to the substrate may be insufficient for subsequent processes.
There is a need for methods and materials for improving the adhesion of metal such as gapfill metal to dielectric surfaces for the fabrication of a variety of electronic devices.